1. Field of the Invention
The present invention relates generally to an upright-type vacuum cleaner, and more particularly, to an air flow structure for an upright-type vacuum cleaner.
2. Description of the Prior Art
A conventional upright-type vacuum cleaner performs cleaning of a cleaning surface such as a floor or a carpet by drawing dust and dirt entrained in air from the outside by using a suction force generated inside of a cleaner body.
As shown in FIG. 1, the conventional upright-type vacuum cleaner has a suction brush 2 disposed at a lower part of the cleaner body 1. The upper inside of the cleaner body 1 has a dust-collecting chamber to embrace a dust bag and the lower inside of the cleaner body 1 has a motor driving chamber 30 having a motor. The dust-collecting chamber includes a dust cover 10. A handle 3 to move the suction brush 1 is disposed on an upper part of the cleaner body 1.
When the motor is driven in the above structure, a strong suction force is generated by the suction brush 2. The air containing dust and filth from the surface to be cleaned facing the suction brush 2 is drawn into the cleaner body 1 by the suction force. The drawn air is discharged through the dust bag in the dust-collecting chamber and into the motor driving chamber 30 through a grill portion disposed between the dust-collecting chamber and the motor driving chamber 30. The dust and dirt in the air is collected in the dust bag and filtered air is discharged to the outside through a discharging grill 40 after passing through the motor driving chamber 30.
When the dust and dirt are collected in the dust bag, the dust bag expands. If the dust bag expands enough to come into close contact with the inside of the dust-collecting chamber, the flow of the air is hindered, the suction force is weakened, and the motor is overloaded. Therefore, the vacuum cleaner has an air flow structure in the dust-collecting chamber.
FIG. 2 is an exploded perspective view showing an upright-type vacuum cleaner having a conventional air flow structure. As shown in FIG. 2, the conventional air flow structure has a plurality of ribs 11 disposed at the dust cover 10 in a lengthwise direction. Accordingly, the expanded dust bag is supported by the ribs 11, and thus some space for the air to flow is defined by the ribs 11 between the dust cover 10 and the dust bag.
However, in the above air flow structure, the ribs 11 are disposed in the dust cover 10 to form the air passage in front of the dust bag. However, the dust bag in the dust-collecting chamber 20 expands in both directions, front and back. Therefore, the air cannot flow easily at the back of the dust bag when fully expanded. Accordingly, there is a problem of weakening of the suction force of the vacuum cleaner when the dust bag expands, which causes the motor to be overloaded.
An object of the present invention is to provide an air flow structure for an upright-type vacuum cleaner to prevent weakening of the suction force and overloading of the motor due to the expansion of dust bag against the dust collecting chamber.
The above object is accomplished by providing an air flow structure for an upright-type vacuum cleaner comprising: a body divided by a partition into a dust-collecting chamber having a dust bag and a motor driving chamber having a motor; an air suction port protruding from an upper part of the dust-collecting chamber in order to draw in air, and having the dust bag disposed around the air suction port; a dust cover closing the dust-collecting chamber and having a plurality of ribs disposed therein in a lengthwise direction in order to form an air passage; a second air passage formed as a concave portion at the rear wall of the dust-collecting chamber, in a lengthwise direction; and a grill portion formed at the partition of the body in order to allow the air of the dust-collecting chamber to flow into the motor driving chamber.
Accordingly, a space for the air to flow both in back of and in front of the dust bag in the dust-collecting chamber is provided. Thus, weakening of the suction force and overloading of the motor due to the expansion of dust bag can be prevented or minimized.